Exposure of U.S. adults to microplastics from commonly-consumed proteins

• Published in: Environmental pollution (1987) Vol. 343; p. 123233
• Main Authors: Milne, Madeleine H., De Frond, Hannah, Rochman, Chelsea M., Mallos, Nicholas J., Leonard, George H., Baechler, Britta R.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.02.2024
• Subjects: Adult; Diet; Environmental Monitoring - methods; Food; Human exposure; Humans; Ingestion; Microplastics; Plant Proteins; Plastics; Proteins; Seafood - analysis; United States; Water Pollutants, Chemical - analysis; United States; Proteins; Microplastics; Plastics; Human exposure; Food; Ingestion
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2023.123233

We investigated microplastic (MP) contamination in 16 commonly-consumed protein products (seafoods, terrestrial meats, and plant-based proteins) purchased in the United States (U.S.) with different levels of processing (unprocessed, minimally-processed, and highly-processed), brands (1 – 4 per product type, depending on availability) and store types (conventional supermarket and grocer featuring mostly natural/organic products). Mean (±stdev) MP contamination per serving among the products was 74 ± 220 particles (ranging from 2 ± 2 particles in chicken breast to 370 ± 580 in breaded shrimp). Concentrations (MPs/g tissue) differed between processing levels, with highly-processed products containing significantly more MPs than minimally-processed products (p = 0.0049). There were no significant differences among the same product from different brands or store types. Integrating these results with protein consumption data from the American public, we estimate that the mean annual exposure of adults to MPs in these proteins is 11,000 ± 29,000 particles, with a maximum estimated exposure of 3.8 million MPs/year. These findings further inform estimations of human exposure to MPs, particularly from proteins which are important dietary staples in the U.S. Subsequent research should investigate additional drivers of MPs in the human diet, including other understudied food groups sourced from both within and outside the U.S. [Display omitted] •We observed microplastic contamination ≥45 μm in 16 U.S. protein products.•Highly-processed products contained the most microplastics per gram.•Microplastic contamination did not differ between brands or store types.•Mean U.S. adult exposure from consuming these proteins is >11,000 microplastics/year.•Maximum U.S. adult exposure from these proteins is ∼3.8 million microplastics/year.